df does not report my root file system

[Ming-Ching Tiew]

This is the output of  these commands :-

# ls -al /dev/ram0 /dev/root
brw-rw----  1  root root 1, 0 July 10 15:30 /dev/ram0
lrwxrwxrwx 1 root root     9 July 10 15:30 /dev/root -> /dev/ram0
# cat /proc/mounts
rootfs / rootfs rw 0 0
/proc /proc proc rw 0 0
# df
Filesystem 1k-blocks Used Available
(blank output except for the header )

This is executed in initramfs. 

Now my problem is that 'df' does not report the root filesystem.
What do I have to do to make it report the root files system ?

Regards.